src/derivepassphrase/_internals/cli_machinery.py (9a259fe) - derivepassphrase.git

cli_machinery.py

# SPDX-FileCopyrightText: 2026 Marco Ricci <software@the13thletter.info>
#
# SPDX-License-Identifier: Zlib

"""Command-line machinery for derivepassphrase.

Warning:
    Non-public module (implementation detail), provided for didactical and
    educational purposes only. Subject to change without notice, including
    removal.

"""

from __future__ import annotations

import abc
import collections
import dataclasses
import enum
import importlib.metadata
import inspect
import logging
import types
import warnings
import weakref
from typing import TYPE_CHECKING, Generic, NamedTuple, TypeVar, Union, cast

import click
import click.shell_completion
from typing_extensions import ParamSpec, final, override

from derivepassphrase import _internals, _types
from derivepassphrase._internals import cli_messages as _msg

if TYPE_CHECKING:
    from collections.abc import (
        Callable,
        Mapping,
        MutableMapping,
        MutableSequence,
        Sequence,
    )
    from typing import TextIO

from typing_extensions import Any, Literal, Self, TypeAlias

PROG_NAME = _internals.PROG_NAME
VERSION = _internals.VERSION
VERSION_OUTPUT_WRAPPING_WIDTH = 72

# Error messages
NOT_AN_INTEGER = "not an integer"
NOT_A_NONNEGATIVE_INTEGER = "not a non-negative integer"
NOT_A_POSITIVE_INTEGER = "not a positive integer"
COMMAND_LINE_NOT_NORMALIZED = "command-line not normalized"

# CLI parsing machinery
# =====================

# Data types and helper functions
# -------------------------------

TrStr: TypeAlias = Union["_msg.TranslatedString", str]
CLISubcommand: TypeAlias = Union[
    "CLITerminalSubcommand", "CLICompositeSubcommand"
]

@dataclasses.dataclass(frozen=True)
class CLIOption:
    """A CLI option."""

names: tuple[str, ...]
    """
    The names for this option, beginning with the canonical long option
    name, then the aliases.
    """
    help: TrStr
    """The help string for this option, including metavars, if any."""
    has_argument: tuple[str, ...] | bool = False
    """
    Whether the option takes an argument or not.  If only certain
    values are permitted, then this attribute lists those values.
    """
    eager: bool = False
    """
    Whether the option is eager, overriding all other arguments on the
    command-line.
    """

@dataclasses.dataclass(frozen=True)
class CLIOptionGroup:
    """A named group of CLI options, with epilog."""

options: tuple[CLIOption, ...]
    """The group contents."""
    title: TrStr
    """The group title."""
    epilog: TrStr = ""
    """The epilog."""

@dataclasses.dataclass(frozen=True)
class CLIArgument:
    """A CLI positional argument."""

name: str
    """The argument name, usually equal to its metavar."""
    choices: tuple[str, ...] | None = None
    """The list of possible values, if applicable."""

_canon_map_cache: MutableMapping[
    CLISubcommand, Mapping[str | None, CLIOption | CLISubcommand]
] = weakref.WeakKeyDictionary()
"""
A weak key mapping from subcommand to canonical name map.  Because the
`canon_map` property is defined on frozen dataclasses (the subcommand
objects), we cannot store the canonical name map on the subcommand
object itself, but must maintain our own cache, without interfering with
garbage collection.
"""

def _check_nonunique_alias(
    name: str,
    cname1: CLIOption | CLISubcommand,
    mapping: Mapping[str | None, CLIOption | CLISubcommand],
    /,
) -> None:
    if name in mapping:  # pragma: no cover [failsafe]
        cname2 = mapping[name]
        cname1str = cname1.names[0]
        cname2str = cname2.names[0]
        msg = (
            f"Non-unique option or subcommand alias {name!r} "
            f"for both {cname1str!r} and {cname2str!r}"
        )
        raise ValueError(msg)

def _check_unique_argument_names(
    arguments: Sequence[CLIArgument],
    /,
) -> None:
    names_seen: set[str] = set()
    for arg in arguments:
        name = arg.name
        if name in names_seen:  # pragma: no cover [failsafe]
            msg = f"Non-unique positional argument name {name!r}"
            raise ValueError(msg)
        names_seen.add(name)

def _check_is_valid_option_name(
    name: str,
    /,
) -> None:
    parts = name.split("-")
    is_short_option = (
        len(parts) == 2  # noqa: PLR2004
        and not any(parts[:1])
        and all(len(p) == 1 for p in parts[1:])
    )
    is_long_option = (
        len(parts) > 2  # noqa: PLR2004
        and not any(parts[:2])
        and all(len(p) >= 1 for p in parts[2:])
    )
    if not (is_short_option or is_long_option):  # pragma: no cover [failsafe]
        msg = f"Invalid option name {name!r}"
        raise ValueError(msg)

def _check_is_valid_subcommand_name(
    name: str,
    /,
) -> None:
    if not name:  # pragma: no cover [failsafe]
        msg = f"Invalid argument/subcommand name {name!r}"
        raise ValueError(msg)

def calculate_canon_map(
    command: CLISubcommand,
    /,
) -> Mapping[str | None, CLIOption | CLISubcommand]:
    """Return a mapping of options and subcommands to canonical names.

Options, positional arguments and further subcommands are mapped
    only up to the next subcommand boundary.  The canonical name of the
    default subcommand (if any) is registered as the name `""`.

Args:
        command:
            A subcommand whose options, positional arguments and
            further subcommands to map.

Returns:
        A mapping of option/subcommand names to their respective
        canonical option/subcommand name, for this subcommand, and
        not including nested subcommands.

Raises:
        ValueError:
            The command contains invalid or duplicate
            option/subcommand names.

"""
    mapping: dict[str | None, CLIOption | CLISubcommand] = {}
    for option_group in command.contents[0]:
        for option in option_group.options:
            for name in option.names:
                _check_is_valid_option_name(name)
                _check_nonunique_alias(name, option, mapping)
                mapping[name] = option
    if isinstance(command, CLITerminalSubcommand):
        for argument in command.contents[1]:
            _check_is_valid_subcommand_name(argument.name)
        _check_unique_argument_names(command.contents[1])
    else:
        for subcommand in command.contents[1]:
            for name in subcommand.names:
                _check_is_valid_subcommand_name(name)
                _check_nonunique_alias(name, subcommand, mapping)
                mapping[name] = subcommand
        if command.contents[2] is not None:
            name = command.contents[2]
            _check_is_valid_subcommand_name(name)
            try:
                canonical_option_or_subcommand = mapping[name]
            except KeyError as exc:  # pragma: no cover [failsafe]
                msg = f"Invalid default subcommand name {name!r}"
                raise ValueError(msg) from exc
            mapping[None] = canonical_option_or_subcommand
    return types.MappingProxyType(mapping)

@dataclasses.dataclass(frozen=True)
class CLITerminalSubcommand:
    """A CLI subcommand without own subcommands."""

names: tuple[str, ...]
    """
    The names for this subcommand, beginning with the canonical subcommand
    name, then the aliases.
    """
    contents: tuple[tuple[CLIOptionGroup, ...], tuple[CLIArgument, ...]]
    """
    The contents of this subcommand: a list of option groups and positional
    arguments.
    """
    prolog: tuple[TrStr, ...]
    """The help text prolog."""
    epilog: tuple[TrStr, ...]
    """The help text epilog."""

@property
    def canon_map(self) -> Mapping[str | None, CLISubcommand | CLIOption]:
        """A mapping of names to the option or subcommand object.

In the general case, the mapping only tables top-level option
        and subcommand names from this subcommand (i.e., nested
        subcommands are excluded), and it may also contain a `None` key,
        pointing to the default subcommand object.

This property accesses and writes to a shared cache, in
        a non-threadsafe manner.

"""
        if self not in _canon_map_cache:
            _canon_map_cache[self] = calculate_canon_map(self)
        return _canon_map_cache[self]

@dataclasses.dataclass(frozen=True)
class CLICompositeSubcommand:
    """A CLI subcommand with own subcommands."""

names: tuple[str, ...]
    """
    The names for this subcommand, beginning with the canonical subcommand
    name, then the aliases.
    """
    contents: tuple[
        tuple[CLIOptionGroup, ...], tuple[CLISubcommand, ...], str | None
    ]
    """
    The contents of this subcommand: a list of option groups, a list of
    subcommands, and an optional default subcommand name.
    """
    prolog: tuple[TrStr, ...]
    """The help text prolog."""
    epilog: tuple[TrStr, ...]
    """The help text epilog."""

@property
    def canon_map(self) -> Mapping[str | None, CLISubcommand | CLIOption]:
        """A mapping of names to the option or subcommand object.

The mapping is for this subcommand only (i.e., excluding nested
        subcommands), and it optionally includes a `None` entry pointing
        to the default subcommand object.

This property accesses and writes to a shared cache, in
        a non-threadsafe manner.

"""
        if self not in _canon_map_cache:
            _canon_map_cache[self] = calculate_canon_map(self)
        return _canon_map_cache[self]

ParsedCommandLineToken: TypeAlias = tuple[str, ...]
ParsedCommandLineSection: TypeAlias = tuple[ParsedCommandLineToken, ...]
ParsedCommandLine: TypeAlias = tuple[
    tuple[CLISubcommand, ParsedCommandLineSection], ...
]

class CommandLineTokenType(str, enum.Enum):
    """The type of a command-line token.

Attributes:
        LONG_OPTION:
            A long option, perhaps with an attached option value.
        SHORT_OPTION:
            A (perhaps trivial) cluster of short options, perhaps
            including an option value.
        POSITIONAL:
            A positional argument.
        END_OF_OPTIONS:
            The `--` pseudo-argument.

"""

LONG_OPTION = "LONG_OPTION"
    """"""
    SHORT_OPTION = "SHORT_OPTION"
    """"""
    POSITIONAL = "POSITIONAL"
    """"""
    END_OF_OPTIONS = "END_OF_OPTIONS"
    """"""

@classmethod
    def classify(cls, token: str, /) -> CommandLineTokenType:
        """Return the type of the given token."""
        if token == "--":  # noqa: S105
            return cls.END_OF_OPTIONS
        if token.startswith("--"):
            return cls.LONG_OPTION
        if token.startswith("-"):
            return cls.SHORT_OPTION
        return cls.POSITIONAL

class ParseState(NamedTuple):
    """The internal state of a command-line parser.

Typically used in a monadic context within the [`ParseResult`][]
    class.

Attributes:
        command_line:
            The unparsed/remaining command-line.
        subcommand:
            A subcommand structure that governs the options, positional
            arguments and subcommands recognized in this section of the
            command line.

"""

command_line: tuple[str, ...]
    subcommand: CLISubcommand

TResult = TypeVar("TResult", bound="ParseResult")
TSuccess = TypeVar("TSuccess")

@dataclasses.dataclass(frozen=True)
class ParseResult(abc.ABC):
    """A monadic CLI parser parse result.

A parse result has three manifestations: "success", "failure", and
    "early exit".  A "success" result can be transformed further by a
    [bound operation][ParseResult.bind] into any of the three
    manifestations, a "failure" or "early exit" result will remain the
    same.  Each manifestation also carries additional information
    specific to this manifestation.

A plain parser state can be wrapped via the [`unit`
    operation][ParseResult.unit].

Attributes:
        state:
            The underlying parser state.

"""

state: ParseState

@classmethod
    def unit(cls, state: ParseState) -> ParseSuccess[None]:
        """Return a wrapped parser state, in the context of the monad."""
        return ParseSuccess(state=state, result=None)

@abc.abstractmethod
    def bind(
        self,
        f: Callable[[ParseState], ParseResult],
        /,
    ) -> ParseResult:
        """Operate on the parser state, in the context of the monad.

Args:
            f:
                An operator to be bound to this parse result.  If the
                parse result is successful, then `f` will be called on
                the embedded parse state, and the return value will be
                returned as the new parse result.  (The new parse result
                is not necessarily successful.)  Otherwise, the old
                parse result will be returned unchanged, and `f` will
                not be called.

Returns:
            A new parse result, obtained by transforming the old parse
            result with `f` if applicable, else by aliasing the old
            parse result.

"""

@final
@dataclasses.dataclass(frozen=True)
class ParseSuccess(ParseResult, Generic[TSuccess]):
    result: TSuccess

@override
    def bind(
        self,
        f: Callable[[ParseState], TResult],
        /,
    ) -> TResult:
        """Operate on the parser state, in the context of the monad.

Args:
            f:
                An operator to be bound to this parse result.  Because
                this parse result is successful, `f` will be called on
                the embedded parse state, and the return value will be
                returned as the new parse result.  The new parse result
                is not necessarily successful.

Returns:
            A new parse result, obtained by transforming the old parse
            result with `f`.

"""
        return f(self.state)

@final
@dataclasses.dataclass(frozen=True)
class ParseEarlyExit(ParseResult):
    result: str

@override
    def bind(
        self,
        f: Callable[[ParseState], ParseResult],
        /,
    ) -> Self:
        """Operate on the parser state, in the context of the monad.

Args:
            f:
                Ignored, because this parse result is not successful.

Returns:
            The old parse result, unchanged.

"""
        del f
        return self

@final
@dataclasses.dataclass(frozen=True)
class ParseFailure(ParseResult):
    error: str

@override
    def bind(
        self,
        f: Callable[[ParseState], ParseResult],
        /,
    ) -> Self:
        """Operate on the parser state, in the context of the monad.

Args:
            f:
                Ignored, because this parse result is not successful.

Returns:
            The old parse result, unchanged.

"""
        del f
        return self

# Parsing stages
# --------------

def _is_valid_option_argument(
    option: CLIOption,
    argument: str,
    /,
) -> bool:
    if isinstance(option.has_argument, bool):
        # If any argument value doesn't matter, then the argument is
        # valid if and only if the option takes an argument.
        return option.has_argument
    return argument in option.has_argument

def _handle_option(
    args: list[str],
    /,
    *,
    state: ParseState,
    old_command_line: collections.deque[str],
) -> ParseFailure | str:
    canon_map = state.subcommand.canon_map
    arg_queue = list(args)
    opt_ = arg_queue.pop(0)
    if opt_ not in canon_map:
        error = f"Unknown option {opt_!r}."
        return ParseFailure(state, error)
    option = cast("CLIOption", canon_map[opt_])
    if option.has_argument:
        if not arg_queue:
            if not old_command_line:
                error = f"Missing argument for option {opt_!r}."
                return ParseFailure(state, error)
            arg_queue.append(old_command_line.popleft())
        value = arg_queue.pop(0)
        if not _is_valid_option_argument(option, value):
            error = f"Invalid argument {value!r} for option {opt_!r}."
            return ParseFailure(state, error)
        return "=".join([option.names[0], value])
    return option.names[0]

# TODO(the-13th-letter): Find a way to include debug logging in this
# parser step.
def normalize_options(
    state: ParseState,
    /,
) -> ParseFailure | ParseSuccess[None]:
    old_command_line = collections.deque(state.command_line)
    new_command_line: collections.deque[str] = collections.deque()
    while old_command_line:
        arg_ = old_command_line.popleft()
        token_type = CommandLineTokenType.classify(arg_)
        # TODO(the-13th-letter): Rewrite using structural pattern matching.
        # https://the13thletter.info/derivepassphrase/latest/pycompatibility/#after-eol-py3.9
        if token_type == CommandLineTokenType.LONG_OPTION:
            arg_queue = arg_.split("=", 1) if "=" in arg_ else [arg_]
            result = _handle_option(  # may consume from old_command_line
                arg_queue,
                state=state,
                old_command_line=old_command_line,
            )
            if isinstance(result, ParseResult):
                return result
            new_command_line.append(result)
        elif token_type == CommandLineTokenType.SHORT_OPTION:
            replacement_args: collections.deque[str] = collections.deque()
            letters = collections.deque(arg_[1:])
            while letters:
                letter = letters.popleft()
                arg_queue = (
                    [f"-{letter}", "".join(letters)]
                    if letters
                    else [f"-{letter}"]
                )
                result = _handle_option(
                    arg_queue,
                    state=state,
                    old_command_line=old_command_line,
                )
                if isinstance(result, ParseResult):
                    return result
                replacement_args.append(result)
                if "=" in result:  # pragma: no cover [external]
                    letters.clear()
            old_command_line.extendleft(reversed(replacement_args))
        else:
            new_command_line.extend([arg_] if arg_ == "--" else ["--", arg_])
            new_command_line.extend(old_command_line)
            old_command_line.clear()
            break
    else:
        new_command_line.append("--")
    return ParseSuccess(
        state._replace(command_line=tuple(new_command_line)), None
    )

def scan_for_eager_options(
    state: ParseState,
    /,
) -> ParseEarlyExit | ParseFailure | ParseSuccess[None]:
    option_groups = state.subcommand.contents[0]
    eager_option_objects = {
        option
        for group in option_groups
        for option in group.options
        if option.eager
    }
    eager_option_names = {
        name for option in eager_option_objects for name in option.names
    }
    command_line = collections.deque(state.command_line)
    canon_map = state.subcommand.canon_map
    while command_line:
        arg_ = command_line.popleft()
        token_type = CommandLineTokenType.classify(arg_)
        if token_type == CommandLineTokenType.LONG_OPTION:
            arg_queue = arg_.split("=", 1) if "=" in arg_ else [arg_]
            long_opt_name = arg_queue.pop(0)
            if long_opt_name not in canon_map:
                # Unknown option.  Either the command-line is faulty,
                # or we default to the default subcommand and let *it*
                # make sense of this option.  Regardless, no early exit
                # has been detected so far, so we are done.
                return ParseSuccess(state, None)
            option = cast("CLIOption", canon_map[long_opt_name])
            if long_opt_name in eager_option_names:
                canon_opt = "=".join([option.names[0], *arg_queue])
                new_state = state._replace(command_line=(canon_opt,))
                return ParseEarlyExit(new_state, canon_opt)
        elif token_type == CommandLineTokenType.END_OF_OPTIONS:
            return ParseSuccess(state, None)
        else:  # pragma: no cover [failsafe]
            return ParseFailure(state, COMMAND_LINE_NOT_NORMALIZED)
    return ParseSuccess(state, None)

def parse_until_subcommand_boundary(
    state: ParseState,
    /,
) -> (
    ParseFailure
    | ParseSuccess[tuple[ParsedCommandLineSection, ParseState | None]]
):
    canon_map = state.subcommand.canon_map
    command_line = collections.deque(state.command_line)
    result: collections.deque[ParsedCommandLineToken] = collections.deque()
    while command_line:
        arg_ = command_line.popleft()
        token_type = CommandLineTokenType.classify(arg_)
        if token_type == CommandLineTokenType.LONG_OPTION:
            arg_queue = arg_.split("=", 1) if "=" in arg_ else [arg_]
            result.append(tuple(arg_queue))
        elif token_type == CommandLineTokenType.END_OF_OPTIONS:
            break
        else:  # pragma: no cover [failsafe]
            return ParseFailure(state, COMMAND_LINE_NOT_NORMALIZED)
    if isinstance(state.subcommand, CLITerminalSubcommand):
        return ParseSuccess(state, (tuple(result), None))
    next_command_line = tuple(command_line)
    next_subcommand_name = command_line.popleft() if command_line else None
    if (
        isinstance(next_subcommand_name, str)
        and next_subcommand_name not in canon_map
        and isinstance(state.subcommand, CLICompositeSubcommand)
        and state.subcommand.contents[2] is not None
    ):
        # Unknown subcommand name; fallback exists. Run the
        # default subcommand and reinterpret the argument
        # (positional/subcommand) within the context of the default
        # subcommand.
        command_line.appendleft(next_subcommand_name)
        next_subcommand_name = None
    if next_subcommand_name not in canon_map:
        # Unknown subcommand name; no fallback exists.
        error = f"Unknown subcommand {next_subcommand_name!r}."
        return ParseFailure(state, error)
    next_subcommand = cast(
        "CLISubcommand", canon_map.get(next_subcommand_name)
    )
    new_state = ParseState(next_command_line, next_subcommand)
    return ParseSuccess(state, (tuple(result), new_state))

def complete(
    state: ParseState,
    /,
) -> ParseSuccess[ParsedCommandLine] | ParseFailure | ParseEarlyExit:
    result: collections.deque[
        tuple[CLISubcommand, ParsedCommandLineSection]
    ] = collections.deque()
    step_state = state
    while True:
        subcommand = step_state.subcommand
        tmp3_result = ParseResult.unit(step_state)
        tmp2_result = tmp3_result.bind(normalize_options)
        tmp1_result = tmp2_result.bind(scan_for_eager_options)
        step_result = tmp1_result.bind(parse_until_subcommand_boundary)
        if isinstance(step_result, (ParseEarlyExit, ParseFailure)):
            return step_result
        section_data, next_state = step_result.result
        result.append((subcommand, section_data))
        if next_state is None:
            return ParseSuccess(step_state, tuple(result))
        step_state = next_state

# Logging
# =======

class ClickEchoStderrHandler(logging.Handler):
    """A [`logging.Handler`][] for `click` applications.

Outputs log messages to [`sys.stderr`][] via [`click.echo`][].

"""

def emit(self, record: logging.LogRecord) -> None:
        """Emit a log record.

Format the log record, then emit it via [`click.echo`][] to
        [`sys.stderr`][].

"""
        click.echo(
            self.format(record),
            err=True,
            color=getattr(record, "color", None),
        )

class CLIofPackageFormatter(logging.Formatter):
    """A [`logging.LogRecord`][] formatter for the CLI of a Python package.

Assuming a package `PKG` and loggers within the same hierarchy
    `PKG`, format all log records from that hierarchy for proper user
    feedback on the console.  Intended for use with [`click`][CLICK] and
    when `PKG` provides a command-line tool `PKG` and when logs from
    that package should show up as output of the command-line tool.

Essentially, this prepends certain short strings to the log message
    lines to make them readable as standard error output.

Because this log output is intended to be displayed on standard
    error as high-level diagnostic output, you are strongly discouraged
    from changing the output format to include more tokens besides the
    log message.  Use a dedicated log file handler instead, without this
    formatter.

[CLICK]: https://pypi.org/projects/click/

"""

def __init__(
        self,
        *,
        prog_name: str = PROG_NAME,
        package_name: str | None = None,
    ) -> None:
        self.prog_name = prog_name
        self.package_name = (
            package_name
            if package_name is not None
            else prog_name.lower().replace(" ", "_").replace("-", "_")
        )

def format(self, record: logging.LogRecord) -> str:
        """Format a log record suitably for standard error console output.

Prepend the formatted string `"PROG_NAME: LABEL"` to each line
        of the message, where `PROG_NAME` is the program name, and
        `LABEL` depends on the record's level and on the logger name as
        follows:

* For records at level [`logging.DEBUG`][], `LABEL` is
            `"Debug: "`.
          * For records at level [`logging.INFO`][], `LABEL` is the
            empty string.
          * For records at level [`logging.WARNING`][], `LABEL` is
            `"Deprecation warning: "` if the logger is named
            `PKG.deprecation` (where `PKG` is the package name), else
            `"Warning: "`.
          * For records at level [`logging.ERROR`][] and
            [`logging.CRITICAL`][] `"Error: "`, `LABEL` is the empty
            string.

The level indication strings at level `WARNING` or above are
        highlighted.  Use [`click.echo`][] to output them and remove
        color output if necessary.

Args:
            record: A log record.

Returns:
            A formatted log record.

Raises:
            AssertionError:
                The log level is not supported.

"""
        preliminary_result = record.getMessage()
        prefix = f"{self.prog_name}: "
        if record.levelname == "DEBUG":  # pragma: no cover [unused]
            level_indicator = "Debug: "
        elif record.levelname == "INFO":
            level_indicator = ""
        elif record.levelname == "WARNING":
            level_indicator = (
                f"{click.style('Deprecation warning', bold=True)}: "
                if record.name.endswith(".deprecation")
                else f"{click.style('Warning', bold=True)}: "
            )
        elif record.levelname in {"ERROR", "CRITICAL"}:
            level_indicator = ""
        else:  # pragma: no cover [failsafe]
            msg = f"Unsupported logging level: {record.levelname}"
            raise AssertionError(msg)
        parts = [
            "".join(
                prefix + level_indicator + line
                for line in preliminary_result.splitlines(True)  # noqa: FBT003
            )
        ]
        if record.exc_info:
            parts.append(self.formatException(record.exc_info) + "\n")
        return "".join(parts)

class StandardCLILogging:
    """Set up CLI logging handlers upon instantiation."""

prog_name = PROG_NAME
    package_name = PROG_NAME.lower().replace(" ", "_").replace("-", "_")
    cli_formatter = CLIofPackageFormatter(
        prog_name=prog_name, package_name=package_name
    )
    cli_handler = ClickEchoStderrHandler()
    cli_handler.addFilter(logging.Filter(name=package_name))
    cli_handler.setFormatter(cli_formatter)
    cli_handler.setLevel(logging.WARNING)
    warnings_handler = ClickEchoStderrHandler()
    warnings_handler.addFilter(logging.Filter(name="py.warnings"))
    warnings_handler.setFormatter(cli_formatter)
    warnings_handler.setLevel(logging.WARNING)

@classmethod
    def ensure_standard_logging(cls) -> StandardLoggingContextManager:
        """Return a context manager to ensure standard logging is set up."""
        return StandardLoggingContextManager(
            handler=cls.cli_handler,
            root_logger=cls.package_name,
        )

@classmethod
    def ensure_standard_warnings_logging(
        cls,
    ) -> StandardWarningsLoggingContextManager:
        """Return a context manager to ensure warnings logging is set up."""
        return StandardWarningsLoggingContextManager(
            handler=cls.warnings_handler,
        )

class StandardLoggingContextManager:
    """A reentrant context manager setting up standard CLI logging.

Ensures that the given handler (defaulting to the CLI logging
    handler) is added to the named logger (defaulting to the root
    logger), and if it had to be added, then that it will be removed
    upon exiting the context.

Reentrant, but not thread safe, because it temporarily modifies
    global state.

"""

def __init__(
        self,
        handler: logging.Handler,
        root_logger: str | None = None,
    ) -> None:
        self.handler = handler
        self.root_logger_name = root_logger
        self.base_logger = logging.getLogger(self.root_logger_name)
        self.action_required: MutableSequence[bool] = collections.deque()

def __enter__(self) -> Self:
        self.action_required.append(
            self.handler not in self.base_logger.handlers
        )
        if self.action_required[-1]:
            self.base_logger.addHandler(self.handler)
        return self

def __exit__(
        self,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        exc_tb: types.TracebackType | None,
    ) -> Literal[False]:
        if self.action_required[-1]:
            self.base_logger.removeHandler(self.handler)
        self.action_required.pop()
        return False

class StandardWarningsLoggingContextManager(StandardLoggingContextManager):
    """A reentrant context manager setting up standard warnings logging.

Ensures that warnings are being diverted to the logging system, and
    that the given handler (defaulting to the CLI logging handler) is
    added to the warnings logger. If the handler had to be added, then
    it will be removed upon exiting the context.

Reentrant, but not thread safe, because it temporarily modifies
    global state.

"""

def __init__(
        self,
        handler: logging.Handler,
    ) -> None:
        super().__init__(handler=handler, root_logger="py.warnings")
        self.stack: MutableSequence[
            tuple[
                Callable[
                    [
                        type[BaseException] | None,
                        BaseException | None,
                        types.TracebackType | None,
                    ],
                    None,
                ],
                Callable[
                    [
                        str | Warning,
                        type[Warning],
                        str,
                        int,
                        TextIO | None,
                        str | None,
                    ],
                    None,
                ],
            ]
        ] = collections.deque()

def __enter__(self) -> Self:
        def showwarning(  # noqa: PLR0913,PLR0917
            message: str | Warning,
            category: type[Warning],
            filename: str,
            lineno: int,
            file: TextIO | None = None,
            line: str | None = None,
        ) -> None:
            if file is not None:  # pragma: no cover [external-api]
                self.stack[0][1](
                    message, category, filename, lineno, file, line
                )
            else:
                logging.getLogger("py.warnings").warning(
                    str(
                        warnings.formatwarning(
                            message, category, filename, lineno, line
                        )
                    )
                )

ctx = warnings.catch_warnings()
        exit_func = ctx.__exit__
        ctx.__enter__()
        self.stack.append((exit_func, warnings.showwarning))
        warnings.showwarning = showwarning
        return super().__enter__()

def __exit__(
        self,
        exc_type: type[BaseException] | None,
        exc_value: BaseException | None,
        exc_tb: types.TracebackType | None,
    ) -> Literal[False]:
        ret = super().__exit__(exc_type, exc_value, exc_tb)
        val = self.stack.pop()[0](exc_type, exc_value, exc_tb)
        assert not val
        return ret

P = ParamSpec("P")
R = TypeVar("R")

def adjust_logging_level(
    ctx: click.Context,
    /,
    param: click.Parameter | None = None,
    value: int | None = None,
) -> None:
    """Change the logs that are emitted to standard error.

This modifies the [`StandardCLILogging`][] settings such that log
    records at the respective level are emitted, based on the `param`
    and the `value`.

"""
    # Note: If multiple options use this callback, then we will be
    # called multiple times.  Ensure the runs are idempotent.
    if param is None or value is None or ctx.resilient_parsing:
        return
    StandardCLILogging.cli_handler.setLevel(value)
    logging.getLogger(StandardCLILogging.package_name).setLevel(value)

# Option parsing and grouping
# ===========================

class OptionGroupOption(click.Option):
    """A [`click.Option`][] with an associated group name and group epilog.

Used by [`CommandWithHelpGroups`][] to print help sections.  Each
    subclass contains its own group name and epilog.

Attributes:
        option_group_name:
            The name of the option group.  Used as a heading on the help
            text for options in this section.
        epilog:
            An epilog to print after listing the options in this
            section.

"""

option_group_name: object = ""
    """"""
    epilog: object = ""
    """"""

def __init__(self, *args: Any, **kwargs: Any) -> None:  # noqa: ANN401
        if self.__class__ == __class__:  # type: ignore[name-defined]
            raise NotImplementedError
        # Though click 8.1 mostly defers help text processing until the
        # `BaseCommand.format_*` methods are called, the Option
        # constructor still preprocesses the help text, and asserts that
        # the help text is a string.  Work around this by removing the
        # help text from the constructor arguments and re-adding it,
        # unprocessed, after constructor finishes.
        unset = object()
        help = kwargs.pop("help", unset)  # noqa: A001
        super().__init__(*args, **kwargs)
        if help is not unset:  # pragma: no branch
            self.help = help

class StandardOption(OptionGroupOption):
    pass

# Portions of this class are based directly on code from click 8.1.
# (This does not in general include docstrings, unless otherwise noted.)
# They are subject to the 3-clause BSD license in the following
# paragraphs.  Modifications to their code are marked with respective
# comments; they too are released under the same license below.  The
# original code did not contain any "noqa" or "pragma" comments.
#
#     Copyright 2024 Pallets
#
#     Redistribution and use in source and binary forms, with or
#     without modification, are permitted provided that the
#     following conditions are met:
#
#      1. Redistributions of source code must retain the above
#         copyright notice, this list of conditions and the
#         following disclaimer.
#
#      2. Redistributions in binary form must reproduce the above
#         copyright notice, this list of conditions and the
#         following disclaimer in the documentation and/or other
#         materials provided with the distribution.
#
#      3. Neither the name of the copyright holder nor the names
#         of its contributors may be used to endorse or promote
#         products derived from this software without specific
#         prior written permission.
#
#     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
#     CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES,
#     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
#     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
#     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
#     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
#     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
#     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
#     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
class CommandWithHelpGroups(click.Command):
    """A [`click.Command`][] with support for some help text customizations.

Supports help/option groups, group epilogs, and help text objects
    (objects that stringify to help texts).  The latter is primarily
    used to implement translations.

Inspired by [a comment on `pallets/click#373`][CLICK_ISSUE] for
    help/option group support, and further modified to include group
    epilogs and help text objects.

[CLICK_ISSUE]: https://github.com/pallets/click/issues/373#issuecomment-515293746

"""

@staticmethod
    def _text(text: object, /) -> str:
        if isinstance(text, (list, tuple)):
            return "\n\n".join(str(x) for x in text)
        return str(text)

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.
    def collect_usage_pieces(self, ctx: click.Context) -> list[str]:
        """Return the pieces for the usage string.

Args:
            ctx:
                The click context.

"""
        rv = [str(self.options_metavar)] if self.options_metavar else []
        for param in self.get_params(ctx):
            rv.extend(str(x) for x in param.get_usage_pieces(ctx))
        return rv

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.
    def get_help_option(
        self,
        ctx: click.Context,
    ) -> click.Option | None:
        """Return a standard help option object.

Args:
            ctx:
                The click context.

"""
        help_options = self.get_help_option_names(ctx)

if (
            not help_options or not self.add_help_option
        ):  # pragma: no cover [external-api]
            return None

def show_help(
            ctx: click.Context,
            param: click.Parameter,  # noqa: ARG001
            value: str,
        ) -> None:
            if value and not ctx.resilient_parsing:
                click.echo(ctx.get_help(), color=ctx.color)
                ctx.exit()

# Modified from click 8.1: We use StandardOption and a non-str
        # object as the help string.
        return StandardOption(
            help_options,
            is_flag=True,
            is_eager=True,
            expose_value=False,
            callback=show_help,
            help=_msg.TranslatedString(_msg.Label.HELP_OPTION_HELP_TEXT),
        )

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.
    def get_short_help_str(
        self,
        limit: int = 45,
    ) -> str:
        """Return the short help string for a command.

If only a long help string is given, shorten it.

Args:
            limit:
                The maximum width of the short help string.

"""
        # Modification against click 8.1: Call `_text()` on `self.help`
        # to allow help texts to be general objects, not just strings.
        # Used to implement translatable strings, as objects that
        # stringify to the translation.
        if self.short_help:  # pragma: no cover [external-api]
            text = inspect.cleandoc(self._text(self.short_help))
        elif self.help:
            text = click.utils.make_default_short_help(
                self._text(self.help), limit
            )
        else:  # pragma: no cover [external-api]
            text = ""
        if self.deprecated:  # pragma: no cover [external-api]
            # Modification against click 8.1: The translated string is
            # looked up in the derivepassphrase message domain, not the
            # gettext default domain.
            text = str(
                _msg.TranslatedString(_msg.Label.DEPRECATED_COMMAND_LABEL)
            ).format(text=text)
        return text.strip()

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.
    def format_help_text(
        self,
        ctx: click.Context,
        formatter: click.HelpFormatter,
    ) -> None:
        """Format the help text prologue, if any.

Args:
            ctx:
                The click context.
            formatter:
                The formatter for the `--help` listing.

"""
        del ctx
        # Modification against click 8.1: Call `_text()` on `self.help`
        # to allow help texts to be general objects, not just strings.
        # Used to implement translatable strings, as objects that
        # stringify to the translation.
        text = (
            inspect.cleandoc(self._text(self.help).partition("\f")[0])
            if self.help is not None
            else ""
        )
        if self.deprecated:  # pragma: no cover [external-api]
            # Modification against click 8.1: The translated string is
            # looked up in the derivepassphrase message domain, not the
            # gettext default domain.
            text = str(
                _msg.TranslatedString(_msg.Label.DEPRECATED_COMMAND_LABEL)
            ).format(text=text)
        if text:  # pragma: no branch
            formatter.write_paragraph()
            with formatter.indentation():
                formatter.write_text(text)

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.  Consider the whole section
    # marked as modified; the code modifications are too numerous to
    # mark individually.
    def format_options(
        self,
        ctx: click.Context,
        formatter: click.HelpFormatter,
    ) -> None:
        r"""Format options on the help listing, grouped into sections.

This is a callback for [`click.Command.get_help`][] that
        implements the `--help` listing, by calling appropriate methods
        of the `formatter`.  We list all options (like the base
        implementation), but grouped into sections according to the
        concrete [`click.Option`][] subclass being used.  If the option
        is an instance of some subclass of [`OptionGroupOption`][], then
        the section heading and the epilog are taken from the
        [`option_group_name`] [OptionGroupOption.option_group_name] and
        [`epilog`] [OptionGroupOption.epilog] attributes; otherwise, the
        section heading is "Options" (or "Other options" if there are
        other option groups) and the epilog is empty.

We unconditionally call [`format_commands`][], and rely on it to
        act as a no-op if we aren't actually a [`click.MultiCommand`][].

Args:
            ctx:
                The click context.
            formatter:
                The formatter for the `--help` listing.

"""
        default_group_name = ""
        help_records: dict[str, list[tuple[str, str]]] = {}
        epilogs: dict[str, str] = {}
        params = self.params[:]
        if (  # pragma: no branch
            (help_opt := self.get_help_option(ctx)) is not None
            and help_opt not in params
        ):
            params.append(help_opt)
        for param in params:
            rec = param.get_help_record(ctx)
            if rec is not None:
                rec = (rec[0], self._text(rec[1]))
                if isinstance(param, OptionGroupOption):
                    group_name = self._text(param.option_group_name)
                    epilogs.setdefault(group_name, self._text(param.epilog))
                else:  # pragma: no cover [external-api]
                    group_name = default_group_name
                help_records.setdefault(group_name, []).append(rec)
        if default_group_name in help_records:  # pragma: no branch
            default_group = help_records.pop(default_group_name)
            default_group_label = (
                _msg.Label.OTHER_OPTIONS_LABEL
                if len(default_group) > 1
                else _msg.Label.OPTIONS_LABEL
            )
            default_group_name = self._text(
                _msg.TranslatedString(default_group_label)
            )
            help_records[default_group_name] = default_group
        for group_name, records in help_records.items():
            with formatter.section(group_name):
                formatter.write_dl(records)
            epilog = inspect.cleandoc(epilogs.get(group_name, ""))
            if epilog:
                formatter.write_paragraph()
                with formatter.indentation():
                    formatter.write_text(epilog)
        self.format_commands(ctx, formatter)

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.  Consider the whole section
    # marked as modified; the code modifications are too numerous to
    # mark individually.
    def format_commands(
        self,
        ctx: click.Context,
        formatter: click.HelpFormatter,
    ) -> None:
        """Format the subcommands, if any.

If called on a command object that isn't derived from
        [`click.Group`][], then do nothing.

Args:
            ctx:
                The click context.
            formatter:
                The formatter for the `--help` listing.

"""
        if not isinstance(self, click.Group):
            return
        commands: list[tuple[str, click.Command]] = []
        for subcommand in self.list_commands(ctx):
            cmd = self.get_command(ctx, subcommand)
            if cmd is None or cmd.hidden:  # pragma: no cover [external-api]
                continue
            commands.append((subcommand, cmd))
        if commands:  # pragma: no branch
            longest_command = max((cmd[0] for cmd in commands), key=len)
            limit = formatter.width - 6 - len(longest_command)
            rows: list[tuple[str, str]] = []
            for subcommand, cmd in commands:
                help_str = self._text(cmd.get_short_help_str(limit) or "")
                rows.append((subcommand, help_str))
            if rows:  # pragma: no branch
                commands_label = self._text(
                    _msg.TranslatedString(_msg.Label.COMMANDS_LABEL)
                )
                with formatter.section(commands_label):
                    formatter.write_dl(rows)

# This method is based on click 8.1; see the comment above the class
    # declaration for license details.
    def format_epilog(
        self,
        ctx: click.Context,
        formatter: click.HelpFormatter,
    ) -> None:
        """Format the epilog, if any.

Args:
            ctx:
                The click context.
            formatter:
                The formatter for the `--help` listing.

"""
        del ctx
        if self.epilog:  # pragma: no branch
            # Modification against click 8.1: Call `str()` on
            # `self.epilog` to allow help texts to be general objects,
            # not just strings.  Used to implement translatable strings,
            # as objects that stringify to the translation.
            epilog = inspect.cleandoc(self._text(self.epilog))
            formatter.write_paragraph()
            with formatter.indentation():
                formatter.write_text(epilog)

# Portions of this class are based directly on code from click 8.1.
# (This does not in general include docstrings, unless otherwise noted.)
# They are subject to the 3-clause BSD license in the following
# paragraphs.  Modifications to their code are marked with respective
# comments; they too are released under the same license below.  The
# original code did not contain any "noqa" or "pragma" comments.
#
#     Copyright 2024 Pallets
#
#     Redistribution and use in source and binary forms, with or
#     without modification, are permitted provided that the
#     following conditions are met:
#
#      1. Redistributions of source code must retain the above
#         copyright notice, this list of conditions and the
#         following disclaimer.
#
#      2. Redistributions in binary form must reproduce the above
#         copyright notice, this list of conditions and the
#         following disclaimer in the documentation and/or other
#         materials provided with the distribution.
#
#      3. Neither the name of the copyright holder nor the names
#         of its contributors may be used to endorse or promote
#         products derived from this software without specific
#         prior written permission.
#
#     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
#     CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES,
#     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
#     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
#     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
#     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
#     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
#     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
#     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
#     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# TODO(the-13th-letter): Remove this class and license block in v1.0.
# https://the13thletter.info/derivepassphrase/latest/upgrade-notes/#v1.0-implied-subcommands
class DefaultToVaultGroup(CommandWithHelpGroups, click.Group):
    """A helper class to implement the default-to-"vault"-subcommand behavior.

Modifies internal [`click.MultiCommand`][] methods, and thus is both
    an implementation detail and a kludge.

"""

def resolve_command(
        self, ctx: click.Context, args: list[str]
    ) -> tuple[str | None, click.Command | None, list[str]]:
        """Resolve a command, defaulting to "vault" instead of erroring out."""  # noqa: DOC201
        cmd_name = click.utils.make_str(args[0])

# Get the command
        cmd = self.get_command(ctx, cmd_name)

# If we can't find the command but there is a normalization
        # function available, we try with that one.
        if (  # pragma: no cover [external-api]
            cmd is None and ctx.token_normalize_func is not None
        ):
            cmd_name = ctx.token_normalize_func(cmd_name)
            cmd = self.get_command(ctx, cmd_name)

# If we don't find the command we want to show an error message
        # to the user that it was not provided.  However, there is
        # something else we should do: if the first argument looks like
        # an option we want to kick off parsing again for arguments to
        # resolve things like --help which now should go to the main
        # place.
        if cmd is None and not ctx.resilient_parsing:
            ####
            # BEGIN modifications for derivepassphrase
            #
            # Instead of using
            #
            #     if click.parsers.split_opt(cmd_name)[0]
            #
            # which splits the option prefix (typically `-` or `--`) from
            # the option name, but triggers deprecation warnings in click
            # 8.2.0 and later, we check directly for a `-` prefix.
            #
            # END modifications for derivepassphrase
            ####
            if cmd_name.startswith("-"):
                self.parse_args(ctx, ctx.args)
            ####
            # BEGIN modifications for derivepassphrase
            #
            # Instead of calling ctx.fail here, default to "vault", and
            # issue a deprecation warning.
            deprecation = logging.getLogger(f"{PROG_NAME}.deprecation")
            deprecation.warning(
                _msg.TranslatedString(
                    _msg.WarnMsgTemplate.V10_SUBCOMMAND_REQUIRED
                )
            )
            cmd_name = "vault"
            cmd = self.get_command(ctx, cmd_name)
            assert cmd is not None, 'Mandatory subcommand "vault" missing!'
            args = [cmd_name, *args]
            #
            # END modifications for derivepassphrase
            ####
        return cmd_name if cmd else None, cmd, args[1:]

# TODO(the-13th-letter): Base this class on CommandWithHelpGroups and
# click.Group in v1.0.
# https://the13thletter.info/derivepassphrase/latest/upgrade-notes/#v1.0-implied-subcommands
class TopLevelCLIEntryPoint(DefaultToVaultGroup):
    """A minor variation of DefaultToVaultGroup for the top-level command.

When called as a function, this sets up the environment properly
    before invoking the actual callbacks.  Currently, this means setting
    up the logging subsystem and the delegation of Python warnings to
    the logging subsystem.

The environment setup can be bypassed by calling the `.main` method
    directly.

"""

def __call__(  # pragma: no cover [external-api]
        self,
        *args: Any,  # noqa: ANN401
        **kwargs: Any,  # noqa: ANN401
    ) -> Any:  # noqa: ANN401
        """"""  # noqa: D419
        # Coverage testing is done with the `click.testing` module,
        # which does not use the `__call__` shortcut.  So it is normal
        # that this function is never called, and thus should be
        # excluded from coverage.
        with (
            StandardCLILogging.ensure_standard_logging(),
            StandardCLILogging.ensure_standard_warnings_logging(),
        ):
            return self.main(*args, **kwargs)

# Actual option groups and callbacks used by derivepassphrase
# ===========================================================

def color_forcing_callback(
    ctx: click.Context,
    param: click.Parameter,
    value: Any,  # noqa: ANN401
) -> None:
    """Disable automatic color (and text highlighting).

Ideally, we would default to color and text styling if outputting to
    a TTY, or monochrome/unstyled otherwise. We would also support the
    `NO_COLOR` and `FORCE_COLOR` environment variables to override this
    auto-detection, and perhaps the `TTY_COMPATIBLE` variable too.

Alas, this is not sensible to support at the moment, because the
    conventions are still in flux. And settling on a specific
    interpretation of the conventions would likely prove very difficult
    to change later on in a backward-compatible way. We thus opt for
    a conservative approach and use device-indepedendent text output
    without any color or text styling whatsoever.

"""
    del param, value
    ctx.color = False

def validate_occurrence_constraint(
    ctx: click.Context,
    param: click.Parameter,
    value: Any,  # noqa: ANN401
) -> int | None:
    """Check that the occurrence constraint is valid (int, 0 or larger).

Args:
        ctx: The `click` context.
        param: The current command-line parameter.
        value: The parameter value to be checked.

Returns:
        The parsed parameter value.

Raises:
        click.BadParameter: The parameter value is invalid.

"""
    del ctx  # Unused.
    del param  # Unused.
    if value is None:
        return value
    if isinstance(value, int):
        int_value = value
    else:
        try:
            int_value = int(value, 10)
        except ValueError as exc:
            raise click.BadParameter(NOT_AN_INTEGER) from exc
    if int_value < 0:
        raise click.BadParameter(NOT_A_NONNEGATIVE_INTEGER)
    return int_value

def validate_length(
    ctx: click.Context,
    param: click.Parameter,
    value: Any,  # noqa: ANN401
) -> int | None:
    """Check that the length is valid (int, 1 or larger).

Args:
        ctx: The `click` context.
        param: The current command-line parameter.
        value: The parameter value to be checked.

Returns:
        The parsed parameter value.

Raises:
        click.BadParameter: The parameter value is invalid.

"""
    del ctx  # Unused.
    del param  # Unused.
    if value is None:
        return value
    if isinstance(value, int):
        int_value = value
    else:
        try:
            int_value = int(value, 10)
        except ValueError as exc:
            raise click.BadParameter(NOT_AN_INTEGER) from exc
    if int_value < 1:
        raise click.BadParameter(NOT_A_POSITIVE_INTEGER)
    return int_value

def common_version_output(
    ctx: click.Context,
    param: click.Parameter,
    value: bool,  # noqa: FBT001
) -> None:
    del param, value
    major_dependencies: list[str] = []
    try:
        cryptography_version = importlib.metadata.version("cryptography")
    except ModuleNotFoundError:
        pass
    else:
        major_dependencies.append(f"cryptography {cryptography_version}")
    major_dependencies.append(f"click {importlib.metadata.version('click')}")

click.echo(
        " ".join([
            click.style(PROG_NAME, bold=True),
            VERSION,
        ]),
        color=ctx.color,
    )
    for dependency in major_dependencies:
        click.echo(
            str(
                _msg.TranslatedString(
                    _msg.Label.VERSION_INFO_MAJOR_LIBRARY_TEXT,
                    dependency_name_and_version=dependency,
                )
            ),
            color=ctx.color,
        )

def print_version_info_types(
    version_info_types: dict[_msg.Label, list[str]],
    /,
    *,
    ctx: click.Context,
) -> None:
    for message_label, item_list in version_info_types.items():
        if item_list:
            current_length = len(str(_msg.TranslatedString(message_label)))
            formatted_item_list_pieces: list[str] = []
            n = len(item_list)
            for i, item in enumerate(item_list, start=1):
                space = " "
                punctuation = "." if i == n else ","
                if (
                    current_length + len(space) + len(item) + len(punctuation)
                    <= VERSION_OUTPUT_WRAPPING_WIDTH
                ):
                    current_length += len(space) + len(item) + len(punctuation)
                    piece = f"{space}{item}{punctuation}"
                else:
                    space = "    "
                    current_length = len(space) + len(item) + len(punctuation)
                    piece = f"\n{space}{item}{punctuation}"
                formatted_item_list_pieces.append(piece)
            click.echo(
                "".join([
                    click.style(
                        str(_msg.TranslatedString(message_label)),
                        bold=True,
                    ),
                    "".join(formatted_item_list_pieces),
                ]),
                color=ctx.color,
            )

def derivepassphrase_version_option_callback(
    ctx: click.Context,
    param: click.Parameter,
    value: bool,  # noqa: FBT001
) -> None:
    if value and not ctx.resilient_parsing:
        common_version_output(ctx, param, value)
        derivation_schemes = set(_types.DerivationScheme)
        supported_subcommands = set(_types.Subcommand)
        click.echo()
        version_info_types: dict[_msg.Label, list[str]] = {
            _msg.Label.SUPPORTED_DERIVATION_SCHEMES: [
                k for k in derivation_schemes if k.test()
            ],
            _msg.Label.UNAVAILABLE_DERIVATION_SCHEMES: [
                k for k in derivation_schemes if not k.test()
            ],
            _msg.Label.SUPPORTED_SUBCOMMANDS: [
                k for k in supported_subcommands if k.test()
            ],
        }
        print_version_info_types(version_info_types, ctx=ctx)
        ctx.exit()

def export_version_option_callback(
    ctx: click.Context,
    param: click.Parameter,
    value: bool,  # noqa: FBT001
) -> None:
    if value and not ctx.resilient_parsing:
        common_version_output(ctx, param, value)
        supported_subcommands = set(_types.ExportSubcommand)
        foreign_configuration_formats = [
            _types.ForeignConfigurationFormat.VAULT_STOREROOM,
            _types.ForeignConfigurationFormat.VAULT_V02,
            _types.ForeignConfigurationFormat.VAULT_V03,
        ]
        click.echo()
        version_info_types: dict[_msg.Label, list[str]] = {
            # Marked as known-but-unavailable, because they are used by
            # subcommands of `derivepassphrase export`, not by the
            # command itself.
            _msg.Label.UNAVAILABLE_FOREIGN_CONFIGURATION_FORMATS: list(
                foreign_configuration_formats
            ),
            _msg.Label.SUPPORTED_SUBCOMMANDS: [
                k for k in supported_subcommands if k.test()
            ],
        }
        print_version_info_types(version_info_types, ctx=ctx)
        ctx.exit()

def export_vault_version_option_callback(
    ctx: click.Context,
    param: click.Parameter,
    value: bool,  # noqa: FBT001
) -> None:
    if value and not ctx.resilient_parsing:
        common_version_output(ctx, param, value)
        foreign_configuration_formats = [
            _types.ForeignConfigurationFormat.VAULT_STOREROOM,
            _types.ForeignConfigurationFormat.VAULT_V02,
            _types.ForeignConfigurationFormat.VAULT_V03,
        ]
        known_extras = [
            _types.PEP508Extra.EXPORT,
        ]
        click.echo()
        version_info_types: dict[_msg.Label, list[str]] = {
            _msg.Label.SUPPORTED_FOREIGN_CONFIGURATION_FORMATS: [
                k for k in foreign_configuration_formats if k.test()
            ],
            _msg.Label.UNAVAILABLE_FOREIGN_CONFIGURATION_FORMATS: [
                k for k in foreign_configuration_formats if not k.test()
            ],
            _msg.Label.ENABLED_PEP508_EXTRAS: [
                k for k in known_extras if k.test()
            ],
        }
        print_version_info_types(version_info_types, ctx=ctx)
        ctx.exit()

def vault_version_option_callback(
    ctx: click.Context,
    param: click.Parameter,
    value: bool,  # noqa: FBT001
) -> None:
    if value and not ctx.resilient_parsing:
        common_version_output(ctx, param, value)
        features = [
            _types.Feature.SSH_KEY,
        ]
        click.echo()

from derivepassphrase.ssh_agent import socketprovider  # noqa: PLC0415

socket_providers: dict[str, bool] = {}
        for key, names in socketprovider.SocketProvider.grouped().items():
            if isinstance(key, _types.BuiltinSSHAgentSocketProvider):
                if not key.is_known_fake_agent():
                    other_names = set(names) - {key}
                    formatted_key = (
                        "{key!s} ({aliases_key!s} {aliases})".format(
                            key=key,
                            aliases_key=_msg.TranslatedString(
                                _msg.Label.FEATURE_ITEM_ALIASES
                            ),
                            aliases=", ".join(sorted(other_names, key=str)),
                        )
                        if other_names
                        else str(key)
                    )
                    socket_providers[formatted_key] = key.test()
            elif key:  # pragma: no cover [external]
                socket_providers[key] = True
        version_info_types: dict[_msg.Label, list[str]] = {
            _msg.Label.SUPPORTED_FEATURES: [k for k in features if k.test()],
            _msg.Label.UNAVAILABLE_FEATURES: [
                k for k in features if not k.test()
            ],
            _msg.Label.SUPPORTED_SSH_AGENT_SOCKET_PROVIDERS: sorted(
                k for k, v in socket_providers.items() if v
            ),
            _msg.Label.UNAVAILABLE_SSH_AGENT_SOCKET_PROVIDERS: sorted(
                k for k, v in socket_providers.items() if not v
            ),
        }
        print_version_info_types(version_info_types, ctx=ctx)
        ctx.exit()

def version_option(
    version_option_callback: Callable[
        [click.Context, click.Parameter, Any], Any
    ],
) -> Callable[[Callable[P, R]], Callable[P, R]]:
    return click.option(
        "--version",
        is_flag=True,
        is_eager=True,
        expose_value=False,
        callback=version_option_callback,
        cls=StandardOption,
        help=_msg.TranslatedString(_msg.Label.VERSION_OPTION_HELP_TEXT),
    )

color_forcing_pseudo_option = click.option(
    "--_pseudo-option-color-forcing",
    "_color_forcing",
    is_flag=True,
    is_eager=True,
    expose_value=False,
    hidden=True,
    callback=color_forcing_callback,
    help="(pseudo-option)",
)

class PassphraseGenerationOption(OptionGroupOption):
    """Passphrase generation options for the CLI."""

option_group_name = _msg.TranslatedString(
        _msg.Label.PASSPHRASE_GENERATION_LABEL
    )
    epilog = _msg.TranslatedString(
        _msg.Label.PASSPHRASE_GENERATION_EPILOG,
        metavar=_msg.TranslatedString(
            _msg.Label.PASSPHRASE_GENERATION_METAVAR_NUMBER
        ),
    )

class ConfigurationOption(OptionGroupOption):
    """Configuration options for the CLI."""

option_group_name = _msg.TranslatedString(_msg.Label.CONFIGURATION_LABEL)
    epilog = _msg.TranslatedString(_msg.Label.CONFIGURATION_EPILOG)

class StorageManagementOption(OptionGroupOption):
    """Storage management options for the CLI."""

option_group_name = _msg.TranslatedString(
        _msg.Label.STORAGE_MANAGEMENT_LABEL
    )
    epilog = _msg.TranslatedString(
        _msg.Label.STORAGE_MANAGEMENT_EPILOG,
        metavar=_msg.TranslatedString(
            _msg.Label.STORAGE_MANAGEMENT_METAVAR_PATH
        ),
    )

class CompatibilityOption(OptionGroupOption):
    """Compatibility and incompatibility options for the CLI."""

option_group_name = _msg.TranslatedString(
        _msg.Label.COMPATIBILITY_OPTION_LABEL
    )

class LoggingOption(OptionGroupOption):
    """Logging options for the CLI."""

option_group_name = _msg.TranslatedString(_msg.Label.LOGGING_LABEL)
    epilog = ""

debug_option = click.option(
    "--debug",
    "logging_level",
    is_flag=True,
    flag_value=logging.DEBUG,
    expose_value=False,
    callback=adjust_logging_level,
    help=_msg.TranslatedString(_msg.Label.DEBUG_OPTION_HELP_TEXT),
    cls=LoggingOption,
)
verbose_option = click.option(
    "-v",
    "--verbose",
    "logging_level",
    is_flag=True,
    flag_value=logging.INFO,
    expose_value=False,
    callback=adjust_logging_level,
    help=_msg.TranslatedString(_msg.Label.VERBOSE_OPTION_HELP_TEXT),
    cls=LoggingOption,
)
quiet_option = click.option(
    "-q",
    "--quiet",
    "logging_level",
    is_flag=True,
    flag_value=logging.ERROR,
    expose_value=False,
    callback=adjust_logging_level,
    help=_msg.TranslatedString(_msg.Label.QUIET_OPTION_HELP_TEXT),
    cls=LoggingOption,
)

def standard_logging_options(f: Callable[P, R]) -> Callable[P, R]:
    """Decorate the function with standard logging click options.

Adds the three click options `-v`/`--verbose`, `-q`/`--quiet` and
    `--debug`, which calls back into the [`adjust_logging_level`][]
    function (with different argument values).

Args:
        f: A callable to decorate.

Returns:
        The decorated callable.

"""
    return debug_option(verbose_option(quiet_option(f)))

# Shell completion
# ================

# TODO(the-13th-letter): Remove this once upstream click's Zsh completion
# script properly supports colons.
#
# https://github.com/pallets/click/pull/2846
class ZshComplete(click.shell_completion.ZshComplete):
    """Zsh completion class that supports colons.

`click`'s Zsh completion class (at least v8.1.7 and v8.1.8) uses
    some completion helper functions (provided by Zsh) that parse each
    completion item into value-description pairs, separated by a colon.
    Other completion helper functions don't.  Correspondingly, any
    internal colons in the completion item's value sometimes need to be
    escaped, and sometimes don't.

The "right" way to fix this is to modify the Zsh completion script
    to only use one type of serialization: either escaped, or unescaped.
    However, the Zsh completion script itself may already be installed
    in the user's Zsh settings, and we have no way of knowing that.
    Therefore, it is better to change the `format_completion` method to
    adaptively and "smartly" emit colon-escaped output or not, based on
    whether the completion script will be using it.

As of `click` v8.2.2, the Zsh completion class also adaptively emits
    colon-escaped output or not, based on the very same criterion.

"""

@override
    def format_completion(
        self,
        item: click.shell_completion.CompletionItem,
    ) -> str:
        """Return a suitable serialization of the CompletionItem.

This serialization ensures colons in the item value are properly
        escaped if and only if the completion script will attempt to
        pass a colon-separated key/description pair to the underlying
        Zsh machinery.  This is the case if and only if the help text is
        non-degenerate.

"""
        help_ = item.help or "_"
        value = item.value.replace(":", r"\:" if help_ != "_" else ":")
        return f"{item.type}\n{value}\n{help_}"

# Our ZshComplete class depends crucially on the exact shape of the Zsh
# completion script.  So only fix the completion formatter if the
# completion script is still the same.
#
# (This Zsh script is part of click, and available under the
# 3-clause-BSD license.)
_ORIG_SOURCE_TEMPLATE = """\
#compdef %(prog_name)s

%(complete_func)s() {
    local -a completions
    local -a completions_with_descriptions
    local -a response
    (( ! $+commands[%(prog_name)s] )) && return 1

response=("${(@f)$(env COMP_WORDS="${words[*]}" COMP_CWORD=$((CURRENT-1)) \
%(complete_var)s=zsh_complete %(prog_name)s)}")

for type key descr in ${response}; do
        if [[ "$type" == "plain" ]]; then
            if [[ "$descr" == "_" ]]; then
                completions+=("$key")
            else
                completions_with_descriptions+=("$key":"$descr")
            fi
        elif [[ "$type" == "dir" ]]; then
            _path_files -/
        elif [[ "$type" == "file" ]]; then
            _path_files -f
        fi
    done

if [ -n "$completions_with_descriptions" ]; then
        _describe -V unsorted completions_with_descriptions -U
    fi

if [ -n "$completions" ]; then
        compadd -U -V unsorted -a completions
    fi
}

if [[ $zsh_eval_context[-1] == loadautofunc ]]; then
    # autoload from fpath, call function directly
    %(complete_func)s "$@"
else
    # eval/source/. command, register function for later
    compdef %(complete_func)s %(prog_name)s
fi
"""
if (
    click.shell_completion.ZshComplete.source_template == _ORIG_SOURCE_TEMPLATE
):  # pragma: no cover [external]
    click.shell_completion.add_completion_class(ZshComplete)

derivepassphrase.git

Add parser stages for the planned new command-line argument parser